This disclosure relates generally to strike constructions for pick tools, particularly but not exclusively strike constructions comprising super-hard material; to picks comprising same, particularly but not exclusively for pavement milling, soil stabilisation, mining and boring into rock formations such as in oil and gas exploration; as well as to methods for making the strike constructions.
U.S. Pat. No. 7,950,746 discloses an attack tool for degrading materials, comprising a base segment, a first wear-resistant segment bonded to the base segment, and a second wear-resistant segment bonded to the first wear-resistant segment at a brazed joint opposite the base segment. Super-hard material is bonded to an end of the second segment, and both segments comprise hard-metal material such as cemented carbide material. At least a portion of exterior surfaces of both the wear-resistant segments proximate the joint comprises a finish ground surface. A disclosed method of manufacturing the attack tool includes braze joining the first and second segments and grinding a braze-induced affected zone proximate the brazed joint. Excess braze material may extrude to the outside of the brazed joint and brazing may result in an “affected zone”, which may be weakened by cracks, depressions, scrapes or other irregularities or imperfections. The affected zone is removed by grinding to a finished surface.
There is a need for super-hard pick tools having sufficiently high working life, and methods for making them efficiently.